6 Best Pond Filters For Koi of 2021

Last update: 2021-02-28

Koi fishes are sensitive to parasites, viruses, lethal ammonia and nitrite. To get rid of these harms, you’ll need a good filter. It keeps the water clean and maintains a healthy environment for your Koi fishes.

Here are my top picks for the best pond filter for koi:

Here are the best pond filters for koi you can buy in 2021:

  • Best Overall: OASE BioSmart 5000 Pond Filter
  • Best For Beneficial Bacteria: Aquascape Submersible Pond Water Filter
  • Best For Medium-Sized Ponds: Goplus Pressure Bio Filter 4000GAL
  • Best For Small Ponds: TotalPond Complete Pond Filter
  • Powerful: XtremepowerUS Koi Pressure Boi Filter
  • Best For Lethal Ammonia Removal: Grech CPF-2500 Pond Bio Pressure Filter UVC
Top 6 Best Pond Filters For Koi
Best Overall
OASE BioSmart 5000 Pond Filter
    Read Our Review
    Best For Beneficial Bacteria
    Aquascape Submersible Pond Water Filter
      Read Our Review
      Best For Medium-Sized Ponds
      Goplus Pressure Bio Filter 4000GAL
        Read Our Review
        Best For Small Ponds
        TotalPond Complete Pond Filter
          Read Our Review
          Powerful
          XtremepowerUS Koi Pressure Boi Filter
            Read Our Review
            Best For Lethal Ammonia Removal
            Grech CPF-2500 Pond Bio Pressure Filter UVC
              Read Our Review

              Best Overall: OASE BioSmart 5000 Pond Filter

              OASE BioSmart 5000 Pond Filter
              OASE BioSmart 5000 Pond Filter
              9Outstanding
              Pros
              • Includes biological and mechanical filtration
              • Promotes beneficial bacteria
              • Filter-cleaning indicator
              • Water temperature display
              • Easy to clean
              Cons
              • Takes up space

              OASE BioSmart 5000 is quite big and heavy, which is designed for medium and big ponds. It can clean ponds up to 5,000 gallons (with no fish). This capacity will be a bit less if the pond is full of fishes.

              The water coming in OASE BioSmart 5000 will go through an innovative Flow-Through filter system. This system includes filter foams that make a great biological filtration, and distinct filter zones that promote beneficial bacteria, which plays an important role in the nitrogen cycle, reducing harmful ammonia. Combining both biological and mechanical filters helps enhance filtration efficiency

              OASE BioSmart 5000 features an indicator to let you know when the filters need to be cleaned. There is also a water temperature display for you to monitor the pond’s temperature at any time. Moreover, OASE BioSmart 5000 is very easy to disassemble and clean, easy maintenance. However, since it is quite big, it may take up a lot of space.

              OASE BioSmart 5000 Pond Filter Specifications

              Dimensions

              23 x 16.1 x 19.1 inches

              Weight

              14.33 pounds

              Capacity

              5,000 gallons

              Highlight Features

              Biological and mechanical filtration

              Filter-cleaning indicator

              Water temperature display

              Verdict

              OASE BioSmart 5000 includes biological and mechanical filtration, for medium to large ponds.

              Best For Beneficial Bacteria: Aquascape Submersible Pond Water Filter

              Aquascape Submersible Pond Water Filter
              Aquascape Submersible Pond Water Filter
              8.8Great
              Pros
              • Small and lightweight
              • Small holes & pre-filtration sponge help reduce pump maintenance
              • Ceramic filtration rings promote beneficial bacteria
              • Removable cage for easy cleaning
              • 3-year Limited Manufacturer
              Cons
              • Needs an additional water pump

              Aquascape Submersible Pond Water Filter is designed for small ponds, up to 800 gallons. It is very small and lightweight, only 4.3 pounds. Besides, you can submerge it into the pond, so it takes nearly zero space.

              Aquascape Submersible Pond Water Filter has small holes on the cage and pre-filtration sponge, preventing large debris from clogging the filter and reducing pump maintenance. Inside the filter, there are ceramic filtration rings, which work as the filtration mechanism and promote beneficial bacteria. The cage is removable for easier cleaning.

              Aquascape Submersible Pond Water Filter comes with a 3-year limited warranty. You can buy the filter with confidence.

              The main drawback of Aquascape Submersible Pond Water Filter is that it needs an additional water pump. So you’ll need to buy a pump separately. Fortunately, the filter can connect to almost any submersible water pump in the market.

              Aquascape Submersible Pond Water Filter Specifications

              Dimensions

              12.9 x 5.7 x 12 inches

              Weight

              4.3 pounds

              Capacity

              800 gallons

              Highlight Features

              Small holes & pre-filtration sponge

              Ceramic filtration rings

              Verdict

              #product_verdict_2

              Best For Medium-Sized Ponds: Goplus Pressure Bio Filter 4000GAL

              Goplus Pressure Bio Filter 4000GAL
              Goplus Pressure Bio Filter 4000GAL
              8.4Good
              Pros
              • Pressure filters with UV purifier
              • Easy to install & maintainance
              • Effectively removes Algae, Bacteria, and Viruses
              Cons
              • Needs an additional water pump

              Goplus Pressure Bio Filter has a built-in UV bulb, which works as a UV purifier. This, together with the pressure filters, effectively removes algae, bacteria, and viruses, keeping the water clean and clear. UV light is among the best method to clean the pond water.

              Goplus Pressure Bio Filter has assemblable parts for easy install and maintenance. This filter is recommended for small to medium ponds, about 1,500 - 2,500 gallons (with fishes). However, it is quite heavy and bulky, cannot be submerged, so it may take some space. Besides, it does require an additional water pump.

              Goplus Pressure Bio Filter 4000GAL Specifications

              Dimensions

              22 x 17 x 17 inches

              Weight

              18 pounds

              Capacity

              1,500 - 2,500 gallons

              Highlight Features

              Pressure filters with UV purifier

              Verdict

              Goplus Pressure Bio with pressure filters and UV purifier is a great choice to keep your pond clean.

              Best For Small Ponds: TotalPond Complete Pond Filter

              TotalPond Complete Pond Filter
              TotalPond Complete Pond Filter
              8.4Good
              Pros
              • 9W UV Clarifier
              • Coarse black filter, Fine blue filter, bio-balls
              • Effectively removes Algae, Bacteria, and Viruses
              • Easy to install & maintainance
              Cons
              • Needs an additional water pump

              TotalPond Complete Pond Filter has the same mechanism as Goplus Pressure Bio - pressure filters with UV purifier, but for smaller ponds. It is recommended for 1,2000-gallon ponds (no fish).

              The pressure filters include a coarse black filter, a fine blue filter, and bio-balls, which clean the water and promote the development of beneficial bacteria. The 9W UV Clarifier kills parasites, viruses, and algae, preventing bad odors and green water.

              TotalPond Complete Pond Filter is much lighter and smaller than Goplus Pressure Bio. Everything else is pretty much the same. TotalPond Complete Pond Filter also requires a separate pump.

              TotalPond Complete Pond Filter Specifications

              Dimensions

              9.6 x 16 x 13 inches

              Weight

              6.3 pounds

              Capacity

              1,200 gallons

              Highlight Features

              Pressure filters with UV purifier

              Verdict

              TotalPond Complete cleans green water and promotes beneficial bacteria, ideal for small ponds.

              Powerful: XtremepowerUS Koi Pressure Boi Filter

              XtremepowerUS Koi Pressure Boi Filter
              XtremepowerUS Koi Pressure Boi Filter
              8.4Good
              Pros
              • 10,000-liter/hour filtration system
              • 13W UV light; clean up to 4000gal pond
              • Effectively removes Algae, Bacteria, and Viruses
              Cons
              • Installation may cause confusion

              XtremepowerUS is a powerful pressure pond filter for koi. It can handle up to 10,000 liters per hour, so it is suitable for 4,000 gal ponds. It features 13W UV light, a powerful UV Clarifier to clean green water.

              Despite having a massive power, XtremepowerUS is not so heavy. It is about 17 lbs, even lighter than Goplus Pressure Bio. Overall, XtremepowerUS is a great choice to control algae and microorganisms for a larger pond. However, the installation may cause confusion, leading to an incorrect setup.

              XtremepowerUS Koi Pressure Boi Filter Specifications

              Dimensions

              14” x 5-3/4" x 6”

              Weight

              17 pounds

              Capacity

              4,000 gallons

              Highlight Features

              Pressure filters with UV purifier

              Verdict

              XtremepowerUS is a powerful pressure filter with UV purifier, ideal for larger ponds.

              Best For Lethal Ammonia Removal: Grech CPF-2500 Pond Bio Pressure Filter UVC

              Grech CPF-2500 Pond Bio Pressure Filter UVC
              Grech CPF-2500 Pond Bio Pressure Filter UVC
              8.6Great
              Pros
              • Biological & mechanical filters
              • 13-watt UV Clarifier
              • Promote the growth of beneficial bacteria
              • Quick cleaning handle
              Cons
              • Does not come with a water pump

              Grech CPF-2500 combines biological filters, mechanical filters, and a UV clarifier for the best filtration performance. So, Grech CPF-2500 not only removes algae and parasites but also promotes the growth of aerobic bacteria, which helps reduce lethal ammonia and nitrite.

              Grech CPF-2500 features a quick cleaning handle. Don’t need to open the filter, just need to circle the handle around and the foams inside are cleaned. Like other filters above, Grech CPF-2500 requires a water pump. So you need to buy it separately.

              Grech CPF-2500 Pond Bio Pressure Filter UVC Specifications

              Dimensions

              12 x 16 x 12 inches

              Weight

              10 pounds

              Capacity

              1,600 gallons

              Highlight Features

              Biological & mechanical filters

              13-watt UV Clarifier

              Verdict

              Grech CPF-2500 combines biological filters, mechanical filters, and a UV clarifier.

              How To Choose The Best Pond Filters For Koi?

              • There are several types of filters you need to know. The first and most simple type is mechanical filters. They are usually made of sponges or foams to filter out debris, dirt, exceeded food, and fish feces. The second type is biological filters, which usually are ceramic filtration rings to promote beneficial bacteria that reduce lethal ammonia and nitrite. And the third type is UV clarifier, which uses UV light to kill algae, parasites, and viruses, keeping the water crystal clear. Typically, a pond filter combines two or all these three types of filters for the best filtration effectiveness.
              • You’ll also want to consider the filter’s dimensions, weight, and submerge ability. These are important specs to plan your setup. The last spec you’ll want to pay attention to is the recommended capacity. Some filters are only suitable for less than 1,000-gallon ponds, some are more powerful that can be used for several thousand gallon ponds.

              Which Brands Make The Best Pond Filters For Koi?

              Oase-living Water

              • OASE was founded in 1949, dedicated to making agricultural and water tools. Over a half-century, OASE has built its worldwide brand on creative designs using water for gardens and public areas.
              • They are the designer and implementer of some famous fountains and lakes across the world, especially in the US, Europe, and China. They also construct water landscapes for gardens and provides water garden tools, such as filters, pumps, garden control systems, an indoor aquatics.
              • Their products and services are famous for their stylish and innovative technologies. When it comes to water gardens and landscapes, OASE is a brand you can count on.

              AquaScape Construction

              • Aquascape is another well-known pond and water construction. It started in 1991 and won the Silver Award for Excellence in Landscape from the Illinois Landscape Contractor’s Association in 2009. Water constructions like ponds, waterfalls & streams, parks and recreation, zoos an aquarium; all of their constructions have a good sense of art.
              • Besides water landscapes, for both residential builds and commercial builds, they also provide water garden tools, including pond filters for koi.
              • Aquascape Submersible Pond Water Filter is one of their best pond filter, which is both compact and high in performance. You should have a look at it in review no.2 above.

              Total Pond

              • Total Pond with over 50 years of creating ponds in backyards is famous for its simplify constructions, dedicated maintenance-services, and high-quality product. They provides a complete service for fish ponds: flow (move water) - fountains and pumps, fill (hold water) - tubes and liners, clean (clarify water) - water treatments, filters & UVs, and decorate (beautiful water) - spitters, lightings & other decors.
              • If you are finding a brand for your backyard water construction, Total Pond is my recommendation.

              FAQs

              How much filter do I need for a koi pond?

              As long as the filter can handle the capacity of the pond, you need only one filter for a koi pond. If your koi pond is about 1,000 gallons, you may want to install a filter that is recommended for 1,500+ gallons. This is because the recommended number is calculated for a pond with no fish. When the pond is full of fishes and their waste, the actual number is quite less than that.

              What filter do I need for my pond?

              There are three types of filters, mechanical filters, biological filters, UV clarifiers. A common filter combines mechanical filters and biological filters to clean the water and promote the growth of beneficial bacteria. Some include a UV clarifier to kill algae, parasites, and viruses.

              You’ll also need a filter that has recommended capacity higher than your pond’s capacity. For example, if your pond is 1,000 gallons, you’ll need a 1,500+ gallon filter.

              How do you filter a koi pond?

              In addition to installing the right filter (answered above) you can add bioaugmentation into the water. Bioaugmentation contains beneficial bacteria & enzymes that help resolve exceed food and neutralize the water’s PH, keeping the water clean and healthy for koi fishes.

              What size of pump do I need with my koi filter?

              Water should travel through the filter once every two hours. So, for a 1,000-gallon pond, you’ll need a 500 GPH (gallons per hour) pump. If your pond is full of fishes, you should double the pump capacity to ensure the water is always clean and clear.

              How often should I clean my filtration system?

              At least one time a month, or better once every two weeks.

              Some filters feature an indicator to tell you when to clean the foams inside. And some filters have a handle for you to clean the inside without opening the filter. You can consider these filters for easier maintenance.

              Conclusion

              Above is my full review of the best pond filters for Koi. Hope that it will help you choose a suitable filter for your Koi pond.

              Harry Ramos
              Harry Ramos

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